ADS1222
SBAS314A − APRIL 2004 − REVISED SEPTEMBER 2004
24 Bit Analog to Digital Converter
with 2 Channel Differential Input Multiplexer
FEATURES
D
240SPS Data Rate with 4MHz Clock
D
20-Bit Effective Resolution
D
Input Multiplexer with Two Differential
D
D
D
D
D
D
D
D
D
Channels
Pin-Selectable, High-Impedance Input Buffer
±5V
Differential Input Range
0.0003% INL (typ), 0.0015% INL (max)
Self-Calibrating
Simple 2-Wire Serial Interface
On-Chip Temperature Sensor
Single Conversions with Standby Mode
Low Current Consumption: 300µA
Analog Supply: 2.7V to 5.5V
DESCRIPTION
The ADS1222 is a 2-channel, 24-bit, delta-sigma ana-
log-to-digital (A/D) converter. It offers excellent perfor-
mance and low power in a TSSOP-14 package. The
ADS1222 is well-suited for demanding, high-resolution
measurements, especially in portable systems and oth-
er space-saving and power-constrained applications.
A delta-sigma modulator and digital filter form the basis
of the A/D converter. The analog modulator has a
±5V
differential input range. An input multiplexer (mux) is
used to select between two separate differential input
channels. A buffer can be selected to increase the input
impedance of the measurement.
A simple, 2-wire serial interface provides all the
necessary control. Data retrieval, self-calibration, and
Standby mode are handled with a few simple
waveforms. When only single conversions are needed,
the ADS1222 can be quickly shut down (Standby mode)
while idle between measurements to dramatically
reduce the overall power consumption. Multiple
ADS1222s can be connected together to create a
synchronously sampling multichannel measurement
system. The ADS1222 is designed to easily connect to
microcontrollers, such as the MSP430.
The ADS1222 supports 2.7V to 5.5V supplies. Power
is typically less than 1mW in 3V operation and less than
1
µ
W during Standby mode.
APPLICATIONS
D
Hand-Held Instrumentation
D
Portable Medical Equipment
D
Industrial Process Control
D
Weigh Scales
TEMPEN
VDD
VREFP VREFN
CLK
AINP1
AINN1
AINP2
AINN2
Mux
Buffer
∆Σ
Modulator
Digital Filter
and
Serial Interface
SCLK
DRDY/DOUT
MUX
BUFEN
GND
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments
semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date. Products
conform to specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all parameters.
Copyright
2004, Texas Instruments Incorporated
www.ti.com
BURR-BROWN [ BURR-BROWN CORPORATION ]
